Change encodeU/SLEB128 to pad to certain number of bytes
Previously the 'Padding' argument was the number of padding
bytes to add. However most callers that use 'Padding' know
how many overall bytes they need to write. With the previous
code this would mean encoding the LEB once to find out how
many bytes it would occupy and then using this to calulate
the 'Padding' value.
See: https://reviews.llvm.org/D36595
Differential Revision: https://reviews.llvm.org/D37494
llvm-svn: 313393
diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index a71a3d4..f601c14 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -297,16 +297,6 @@
WasmObjectWriter::~WasmObjectWriter() {}
-// Return the padding size to write a 32-bit value into a 5-byte ULEB128.
-static unsigned PaddingFor5ByteULEB128(uint32_t X) {
- return X == 0 ? 4 : (4u - (31u - countLeadingZeros(X)) / 7u);
-}
-
-// Return the padding size to write a 32-bit value into a 5-byte SLEB128.
-static unsigned PaddingFor5ByteSLEB128(int32_t X) {
- return 5 - getSLEB128Size(X);
-}
-
// Write out a section header and a patchable section size field.
void WasmObjectWriter::startSection(SectionBookkeeping &Section,
unsigned SectionId,
@@ -341,12 +331,11 @@
report_fatal_error("section size does not fit in a uint32_t");
DEBUG(dbgs() << "endSection size=" << Size << "\n");
- unsigned Padding = PaddingFor5ByteULEB128(Size);
// Write the final section size to the payload_len field, which follows
// the section id byte.
uint8_t Buffer[16];
- unsigned SizeLen = encodeULEB128(Size, Buffer, Padding);
+ unsigned SizeLen = encodeULEB128(Size, Buffer, 5);
assert(SizeLen == 5);
getStream().pwrite((char *)Buffer, SizeLen, Section.SizeOffset);
}
@@ -453,8 +442,7 @@
static void
WritePatchableLEB(raw_pwrite_stream &Stream, uint32_t X, uint64_t Offset) {
uint8_t Buffer[5];
- unsigned Padding = PaddingFor5ByteULEB128(X);
- unsigned SizeLen = encodeULEB128(X, Buffer, Padding);
+ unsigned SizeLen = encodeULEB128(X, Buffer, 5);
assert(SizeLen == 5);
Stream.pwrite((char *)Buffer, SizeLen, Offset);
}
@@ -464,8 +452,7 @@
static void
WritePatchableSLEB(raw_pwrite_stream &Stream, int32_t X, uint64_t Offset) {
uint8_t Buffer[5];
- unsigned Padding = PaddingFor5ByteSLEB128(X);
- unsigned SizeLen = encodeSLEB128(X, Buffer, Padding);
+ unsigned SizeLen = encodeSLEB128(X, Buffer, 5);
assert(SizeLen == 5);
Stream.pwrite((char *)Buffer, SizeLen, Offset);
}